Control Technical Research Of Microgrid Inverter

The combination of micro grid formed by distributed generation and the main grid is the development trend of the future power system. However, a large number of devices are applied when connecting to grid, and power electronic devices within micro-grid will lead to power quality decline in micro-grid. The control of inverter that not only achieve input energy to the grid but also improve the micro-grid power quality research will become a research focus.This paper analyses the main control methods of inverter based micro-grid, and simulation is conducted. This paper also analyses the course of harmonic in the micro-grid and the working principle of active power filter. In order to make full use of the inverter of the micro-grid, improve the power quality when connect the distribute generation units to the main grid. This paper proposes a new control algorithm which is based on the characteristic of the distribute generation sources, by applying the control technique which improves the grid power quality of active power filter to distribute generation inverter control, forming a new control ideas, controlling the inverter to compensate the harmonic in the grid to improve the grid power quality while transmit the active power to the grid.Using instantaneous reactive power theory based ip-iq harmonic current detect method to detect the harmonic current in the micro-grid; using phase-locked loop technique to achieve real-time grid phase tracking. To deal with the problem of the static error when uses PI to control ac components, this paper proposes the control method based on rotating coordinate system, translate the 5,7,11,13 order harmonic current to dc components to achieve zero state error. Simulation is performed to verify the validity of this method.This paper uses the digital signal processor TMS320F2812 as the main control chip, designed and made the main circuit and the control circuit, and built the system experiment platform. Through the control of the inverter in the micro-grid, verifies the effectiveness of the research work.